No preliminary certificate granted under the provisions of this section shall be valid after one year from its date or after such further period, not exceeding one year, as may be authorized by the commissioner upon cause shown, unless the 500 applicants required in this chapter have been secured and the organization has been completed as provided in this chapter. The articles of incorporation and all other proceedings thereunder shall become null and void in one year from the date of the preliminary certificate, or at the expiration of the extended period, unless the society shall have completed its organization and received a certificate of authority to do business as provided in this chapter.